Ranjit Thakur, Novartis Pharma AG, CHBS, WSJ-145, Lichtstrasse 35, CH-4056 Basel, Switzerland and Maike Lohrmann, Novartis Animal Health Inc., Schwarzwaldallee 215, CH-4058, Basel, Switzerland.
Co-formulation of drug and excipient is one of the new concept coming in Pharma industry. Co-formulation can lead either to coating/encapsulation/solid solution or co-precipitation in different physical forms. Coating/encapsulation can be used for controlled release or taste masking of drugs. Spray drying or melt extrusion are two of the processes which are used in industry commonly to achieve co-formulation. These processes typically suffer from poor reproducibility and process control. At the same time these processes also yield high residual solvent content, high energy consumption and longer processing time. To overcome these challenges supercritical fluid (SCF) based antisolvent method is proposed and studied in this work.
Novartis drug “A” is used as an API and two polymers PLGA and Eudragit EPO are used in this work for co-formulation. Effect of drug to polymer ratio was studied by maintaining same thermodynamic conditions in a SCF based antisolvent system. With Eudragit EPO, it was observed that at higher drug loading, drug was precipitated into crystalline form with polymer coating. Maximum coating was observed at 70 to 30 drug to polymer ratio. But as polymer ratio increased, solid solution of drug and polymer was observed. With PLGA, one trial was conducted which showed good coating over the crystalline drug. Product was analyzed using SEM, Confocal Raman Microscopy, DSC, XRD and dissolution rate. On basis of these analysis, it was concluded that SCF process provides good approach for co-formulation and quality of co-formulation product can be tuned in this process.